You can edit your personal phone number on the "Co-workers & Groups" Page. An explanation with images is given below -
Go to the 'Co-workers & Groups" page on the dashboard and then click on the gear icon right next to your (or whoever's) name
A pop-up opens up. Enter the user details and number. (Enter 0 followed by mobile number)
Once you have entered these details, you will find that your number is configured. Also, to verify the newly added number, you need to place a missed call from this newly added number to 09513885656.
"If you have any questions or concerns, please connect with us using the chat widget on your Exotel Dashboard or Whatsapp us on 08088919888."